For some time, it has been known to transfer a pigmented vinyl (PVC) graphic originating in a multilayer web, to a garment. One such technique is disclosed in U.S. Pat. No. 3,660,212 (Liebe). Liebe discloses a web having a paper release sheet, a pigmented PVC film or coated layer carried on the release sheet, and a thermoplastic vinyl adhesive layer carried on the PVC layer. The desired graphic, such as a letter of the alphabet, is die-cut in reverse image through all the layers and the release sheet. Individual cut letters are carefully placed on the fabric, adhesive side down, to form a word or the like. Heat and pressure are applied through the exposed, paper side of the cut letters, until the adhesive bonds to the fabric. After the letters cool, the paper is pulled away, leaving the pigmented PVC layer of each letter adhered to the garment as the visible graphic.
U.S. Pat. No. 4,423,106 (Mahn) discloses a web usable in a similar manner for applying graphics to a fabric. The release sheet carries a pigmented polyurethane layer which provides the visible graphic, and the adhesive carried by the polyurethane layer, is polyester.
In Liebe, U.S. Pat. No. 5,112,423, is disclosed an embodiment for transferring a graphic to fabric, wherein the release sheet is a clear polyester, the PVC graphic layer is a partially carboxylated PVC, and the adhesive layer is an encapsulating thermoplastic. This web is intended for computer cutting of the graphic pattern in reverse image, through the adhesive and pigmented layers, but not through the release sheet. After cutting, the unwanted portions of the pigmented and adhesive layers are peeled, or "weeded" away, leaving a multi-unit graphic pattern, such as a word, in reverse image on the release sheet. The release sheet is positioned so that the adhesive side of the graphics pattern is in contact with the fabric. Partial carboxylation of the PVC pigmented layer is deemed necessary to provide sufficient adhesion between the PVC layer and the polyester release sheet, to prevent shifting or premature lifting while the letters are being cut and weeded, and while the cut web is being positioned relative to the garment.
In the techniques described immediately above, the full thickness of the PVC letter is transferred to the garment via the adhesive layer as the letter detaches from the release sheet. Another technique is known whereby a specially treated PVC ink layer is carried by a paper release sheet, without an adhesive layer. The inked side is placed on the fabric. Upon heating, the ink portion constituting, e.g., a letter, adheres to the fabric directly, but "splits" as the release sheet is pulled away, thereby leaving some of the letter material adhered on the release sheet. In essence, when the letter is heated, foaming agents or the like in the ink weaken the cohesiveness of the ink material, so that approximately one half the original thickness adheres to the release sheet, while the other half of the thickness bonds to the garment. This is sometimes referred to as the "hot split" technique. Hot split transfer is usually performed by a screen print process. Sometimes, a powdered adhesive is sprinkled on the ink layer before placing the ink layer against the fabric, to enhance bonding.
It would be desirable to provide a web material suitable for conventional or hot split thermal transfer to garments and the like with a single material. It would further be desirable to provide a web employing a transparent release sheet from which graphics patterns may be "kiss cut" and unwanted portions weeded away without resort to a carboxylated PVC.